Numerical simulation setup. We use DEM with frictional interactions modeled by a Hookean contact law with energy dissipation [1]} to implement a series of three-dimensional shearing simulations in dry and submerged conditions. The setup is shown in Fig.REF (a). We establish periodic boundaries in both x - and y - directions, and set up two rough plates vertical to the z - direction to apply the shear velocity in the x - direction. The bottom plate is fixed in the z-direction, while the top plate exerts a constant pressure to the granular system. The system contains 2800 spherical particles, their radii are uniformly distributed in the range of 0.07\(-\) 0.1 cm, their density is 1.18 g/cm\(^3\) , the normal stiffness is \(5\times 10^{7}\)  dyn/cm, and the tangential stiffness is half of the normal one. The restitution coefficient and the frictional coefficient are 0.2 and 0.3, respectively.
The shear rate and the confining pressure are in the range of 0.15 - 50 s\(^{-1}\)  and 80 - 300 Pa. For the submerged condition, the interstitial fluid viscosities vary from 0.001 to 10 dyn\(\cdot \) s/cm\(^{2}\) .
The particles are subjected to three types of forces: contact force, drag force, and lubrication forces, which will be discussed in the Method Section.
<FIGURE><FIGURE>